Laser Hair Removal
Jolly, Aaron; Gupta, Sameer; Auerbach, Eric; Loaknauth, Nicholas; Drost, Laurens
Laser hair removal, through a process known as selective photothermolysis, is a new trendy way to remove all that unwanted hair. Traditional methods such as waxing, tweezing, shaving and electrolysis each have their disadvantages. However, selective photothermolysis provides a simple and relatively painless way to achieve that hair free physique. From our knowledge of the procedure, we found that the most ideal way to model the hair follicle would be in an axis-symmetric model that divides the follicle and its surrounding tissue in half. The follicle was modeled at a depth of .0035m. Other parts of the hair are neglected as we concluded them to be insignificant. After calculating the laser?s power and inputting it as a flux over the surface of the follicle, we found very pleasing results that agree with our target values. These values include a threshold of 60 degrees C for the follicle in order to completely damage it and a threshold of 50 degrees C for the skin that would cause a mild pinching sensation because of the minute sizes we are dealing with. To obtain optimal results the following three laser parameters were varied: fluency, pulse duration and thermal relaxation time. After rigorous testing we found the optimum values as follows: pulse duration of 10ms, thermal relaxation time of 40ms and finally a fluency of 50 J/cm^2. We also found through sensitivity analysis that the specific heat and conductivity do not vary with temperature within a certain range. However, density proved to be very significant and varied drastically with temperature change within the follicle.
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